The research paper published by IJSER journal is about Experimental study on Masonry Infill Material Properties 1

ISSN 2229-5518

Experimental study on Masonry Infill Material

Properties

Palanisamy. M., Premalatha. J.

Abstract — Infills walls are constructed using different types of structural blocks such as clay bricks, fly ash bricks, solid concrete blocks, hollow and cellular blocks. Constructions of bricks or blocks with cement mortar are called masonry. Masonry structures are durable in nature and are resistant to severe climatic conditions. They also accommodate minor earthquake disturbances and normally will not lead to failure in differential settlement of foundations. The factors governing the strength of a masonry structure includes brick strengt h, mortar strength, elasticity, workmanship, brick uniformity and the method used to lay bricks. In this experimental study fly ash brick prism and clay brick prisms of sizes 230 x 230 x 300mm with CM1:4, CM1:5 and CM1:6 mix proportions were used. The compressive strength and modulus of elasticity tests was compared with curing period of 7th and 28th day’s specimens of 3 each and of totally 108 prisms. The results of fly ash brick masonry prism proved that it has achieved maximum compressive strength and young’s modulus.

Index Terms— Brick masonry, Brick prism, Cement mortar, Clay bricks, Compressive strength, Fly ash bricks, Modulus of Elasticity

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1 INTRODUCTION

Masonry units are of several types such as clay bricks, fly ash bricks, concrete blocks, line based blocks, stones etc. Brick masonry is a common construction material in India because of its abundance, low cost, good sound and heat insulation properties, and availability of skilled labour. Masonry is extensively used in India as infill walls in reinforced concrete buildings. Analysis and design of buildings with masonry require material properties of masonry. [1,2] Bricks are obtained by moulding clay in rectangular shape, dried and burned.
Fly ash bricks are made by fly ash which is obtained as a waste material from burning coal or lignite in varies industries, especially in power stations. Lime or cement is added to give the bricks required strength. These are preferred because of its durability, strength, reliability and cost etc. Generally the choice is governed by local availability, compressive strength, fire resistance, cost case of construction etc. Compressive behaviour of masonry is typically a non elastic, non homogeneous and anisotropic material composed of two materials of quite different properties.
Under lateral loads, masonry does not behave elastically even in the range of small deformations. Masonry is very weak in tension because it is composed of two different materials distributed at regular intervals and the bond between them is very weak. Therefore, masonry is normally provided and expected to resist only the compressive forces. During compression of masonry prisms constructed with stronger and stiffer bricks, mortar of bed joint has a tendency to expand laterally more than the bricks because of lesser stiffness.

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Assistant Professor [SG], [Research Scholar, Anna University], Civil Engineering Department, Tamilnadu College of Engineering, Coimbatore, Tamilnadu, India.PIN: 641 659. PH- +91 9443822024. Email: palanisamym@rediffmail.com.

Professor and Head, Civil Engineering Department, Kumaraguru College of Technology, Coimbatore,Tamilnadu,India.PIN: 641 006. Email: premaravi_30@yahoo.com
However, mortar is confined laterally at the brick-mortar interface by the bricks because of the bond between them, therefore, shear stresses at the brick – mortar interface result in an internal state of stress which consists of triaxial compression in bricks.[2] Limited experimental research has been carried out in India to determine the stress - strain curves of masonry typically constructed in the Indian industry.[3] In the present study the experimental testing of masonry prisms is performed to obtained the compressive strength and stress - strain curves.

2 PROPERTIES OF MATERIALS

The properties of materials were tested as per Indian
Standard codes [5-8]

CEMENT

Specific Gravity : 3.1
Normal Consistency : 32%
Initial Setting : 30 minutes
Final Setting : 600 minutes

SAND

Fineness Modulus : 2.70
Fine aggregate grading : Zone II
Specific Gravity, G : 2 .44
Bulk density : 1720kg/m3

BRICKS

TABLE 1

Compressive Strength of bricks

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The research paper published by IJSER journal is about Experimental study on Masonry Infill Material Properties 2

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TABLE 2

Water Absorption

Weight of Bricks

Average Weight of Clay brick : 2.714 kg
Average Weight of Fly Ash brick : 3.031 kg

3 MIX PROPORTION

In this experimental study, clay bricks and fly ash
bricks were used. Total numbers of specimens are mentioned
below:

TABLE 3

Total numbers of specimens

4 PRISM CASTING AND CURING

Casting of prisms (Fig.1) were made 230mm x 230mm
x 300mm in dimension for using CM 1:4, CM 1:5, and CM 1:6
mix proportions and allowed to curing (Fig.2) of 7 and 28 days
with using of gunny bags .

Fig. 1 Casting of Clay brick and Fly Ash Prisms

Fig. 2 Curing of Clay brick Prisms

5 TESTING PROCEDURE Compressive Strength Test

Universal testing machine (UTM) of capacity 1000kN
was used for the testing of compressive strength of Prism spe-
cimens (Fig.3-6). The prisms were placed at the centre of the
loading platform of UTM tested under axial compression
without any eccentricity. The load is increased gradually till
the crushing of specimens. The load at which the specimen failed was taken as the Ultimate compression strength. Test- ing procedure were followed as per relevant IS Code of

Practices.[9]

Fig. 3 Test set up for Compressive Strength

Fig. 4 Compressive Strength Test for Fly Ash Brick

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Fig. 5 Compressive Strength Test for Fly Ash Brick

Fig. 6 Compressive Strength Test for Clay Brick

Young’s Modulus Test

The prisms were placed with the frame set up in which a compressometer (dial gauge) is fixed at one lateral directions ( X or Z) of the frame in which other three faces of the frame is fitted with adjustable screws with pivot rod at centre of the specimen to tighten the frame with masonry prism. The compressometer is centrally pivoted with the prism to observe the lateral movement of prism during axial loading. Set the dial gauge (least count = 0.01) at the centre of

Fig. 7 Test set up for Modulus of Elasticity

Fig. 8 Modulus of Elasticity Test on Fly Ash Brick

6 TEST RESULTS Compressive Strength Results

Compressive strength results (Table 4 & 5) of the ma- sonry prisms represented graphically is shown in the Fig.9 & Fig.10
prism surface. The load was applied axially at a uniform rate and corresponding readings were noted at equal intervals un- til the prism failure occurred. The tests were carried out
1000kN capacity Universal testing machine (UTM). The test
set up is shown in the Fig.7 &Fig.8

1.2

1

0.8

0.6

0.4

0.983

0.92

1.066

0.958

1.046

0.816

Clay Brick

Flyas h Brick

0.2

0

CM 1:4 CM 1:5 CM 1:6

Mortar Type

Fig. 9 Compression Strength for Bricks at 7 days

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TABLE 4

Compressive Strength - Masonry Prism - 7days

Results for Young’s Modulus

Stress strain curve of the clay bricks and fly ash bricks represented graphically in the Fig.11-14

CLAY BRICKS 7 DAYS

1.4

1.2

1

0.8

0.6

0.4

0.2

0

-0.001 0 0.001 0.002 0.003 0.004

STRAIN

CM 1:4

CM 1:5

CM 1:6

TABLE 5

Compressive Strength - Masonry Prism - 28days

Fig. 11 Stress Strain for Clay Brick Masonry Prism

(7days)

CLAY BRICK 28DAYS

1.8

1.6

1.4

1.2

1

0.8

0.6

0.4

0.2

0

-0.0002 0 0.0002 0.0004 0.0006 0.0008 0.001

STRAIN

CM1:4

CM1:5

CM1:6

3

2.5

2

2.728

2.155 2.268

Clay Brick

Fig. 12 Stress Strain for Clay Brick Masonry Prism

(28days)

FLYASH BRICK - 7DAYS

1.4

1.5

1

0.5

0

1.172 1.164 1.058

CM 1:4 CM 1:5 CM 1:6

Mortor Type

Flyas h Brick

1.2

1

0.8

0.6

0.4

0.2

0

-0.002 0 0.002 0.004 0.006

CM 1:4

CM 1:6

CM 1:5

Fig. 10 Compression Strength for Bricks at 28 days

STRAIN

Fig. 13 Stress Strain for Fly Ash Brick Masonry Prism

(7days)

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2

1.5

1

0.5

0

FLYASH BRICK - 28DAYS

CM 1:4

CM 1:6

CM 1:5

8 CONCLUSION

Based on the results obtained through graphically
and analytically, it is found that, the compressive strength of
28 days cured clay bricks prisms and fly ash bricks prisms
were increased significantly than the 7 days cured clay bricks
prisms and fly ash bricks prisms. Further, the compressive
strength of 28 days cured fly ash bricks prisms of CM ratio
1:4 were found to be increased significantly at the rate of 132%
than the clay bricks prisms, the compressive strength of 28
days cured fly ash bricks prisms of CM ratio 1:5 were found
to be increased significantly at the rate of 85 % than the clay

-0.0002 0 0.0002 0.0004 0.0006 0.0008

STRAIN

Fig. 14 Stress Strain for Fly Ash Brick Masonry Prism

(28days)

7 RESULT AND DISCUSSIONS

Compressive testing of masonry prisms were con- ducted using two different bricks and three cement mortar ratios viz. 1:4, 1:5 and 1:6.(Fig.9 and 10) It is found that, the Compressive strength of clay bricks masonry prisms for, 7 days cured were 0.983N/mm2, 1.066 N/mm2 and 0.816 N/mm2 for the ratio of 1:4, 1:5 and 1:6 respectively and the Compres- sive strength of fly ash bricks masonry prisms for 7 days cured were 0.920N/mm2, 0.958 N/mm2 and 1.046 N/mm2 for the ratio of 1:4, 1;5 and 1:6 respectively. (Table. 4) The Compressive strength of clay bricks masonry prisms for, 28 days cured were 1.172 N/mm2, 1.164 N/mm2 and 1.058 N/mm2 for the ratio of 1:4, 1:5 and 1:6 respectively and the Compres- sive strength of fly ash bricks masonry prisms for 28 days cured were 2.728 N/mm2, 2.155 N/mm2 and 2.268 N/mm2 for the ratio of 1:4, 1:5 and 1:6 respectively. (Table.5). Based on the test results, it has been observed that, there is a considerable increase in the compressive strength for fly ash bricks than the clay bricks.
Similarly, Young’s Modulus value also obtained for clay bricks (Fig.11 and 12) and fly ash bricks (Fig.13 and 14) masonry prism for 7 days and 28 days cured. The graphs drawn based on the young’s modulus value obtained for both clay bricks and fly ash bricks masonry prism. It is observed that, the stress strain curve increased linearly gradually for 7 days cured samples and the stress strain curve for 28 days cured samples. It is shown that, for the 28 days cured clay bricks, the stress value of 0.8 N/mm2 (CM1:4), 0.4 N/mm2 (CM1:5) and 1.1 N/mm2 (CM1:6), there was no strain. It has maintained its constancy up to the above mentioned level. It is shown that, for the 28 days cured fly ash bricks, the stress value of 0.8 N/mm2( CM1:4), 0.4 N/mm2 and maintained its constancy up to 1.2 N/mm2 ( CM1:5) and 1.2 N/mm2 (CM1:6), there was no strain. It has maintained its constancy up to the above mentioned level.
bricks prisms and the compressive strength of 28 days cured fly ash bricks prisms of CM ratio 1:6 were found to be increased significantly at the rate of 114% than the clay bricks prisms.
The average Young’s Modulus of Clay Brick prism of CM 1: 4 were found to be 8463 N/mm2 and for Fly ash brick prisms were found to be 13693 N/mm2, Clay Brick prism of CM 1: 5 were found to be 2783 N/mm2 and for Fly ash brick prisms were found to be 7740 N/mm2 and Clay Brick prism of CM 1: 6 were found to be 8675 N/mm2 and for Fly ash brick prisms were found to be 10470 N/mm2. It is evident that, the young’s modulus of fly ash brick prisms of CM ratio of 1:4, 1:5 and 1:6 is found to be higher than the clay brick prisms of sim- ilar CM ratios. Based on the experimental study revolves that, the fly ash brick prism were found to give higher compres- sive strength and higher Young’s Modulus when compared to clay Brick prisms.
Further, the fly ash brick prisms will improve the strength of the masonry and also can accommodate the minor earthquake disturbances and resist the all kind of lateral loads considerably.

9 REFERENCES

1) Hemant B. Kaushik, Durgesh C. Rai and Sudhir K. Jain,
“Uniaxial compressive stress-strain model for clay brick
masonry”. Current Science. Vol.92, No.4, 2007, 497-501.
2) Hemant B. Kaushik, Durgesh C. Rai and Sudhir K. Jain,
“Stress- Strain Characteristics of clay brick masonry under
uniaxial compression”. Journal of Materials in civil Engi-
neering © ASCE / Vol. 19, No. 9, September 1, 2007.
3) Sarangapani,G., Venkataramaretty,B.V. and Jagadesh,K.S.,
“Structural charactristics of bricks, mortar and masonry”.
J.Struct. Engg. (India), 2002, 29,101-107.
4) W.ScottMcNary and Daniel P.Abrams, “Mechanics of ma-
sonry in compression”. Journal of Structural Engineering
Vol.111, No.4, April1985.
5) IS 1077 – 1997 : Common burnt clay building bricks– spe-
cifications
6) IS 2116: 1980 Specification for sand for masonry mortars.
7) IS 2250: 1981 Code of practice for preparation and use of
masonry mortars
8) IS 3466 : 1988 Specification for masonry cement
9) IS 3495: Part 1 to 4: 1992 Methods of Tests of Burnt

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